This disclosure is directed to a stump grinding mechanism.
More specifically, it is a removable insert which is mounted and dismounted from a stump grinding wheel for the express purpose of dressing or trimming the stump grinding wheel periodically by changing or otherwise replacing the teeth as they wear. The replaceable teeth in the stump grinder of this disclosure are especially long use teeth. This is one of the benefits of the disclosed construction, namely that use on a repeated and extended basis permits a very long life. Even when a tooth is worn, the tooth can be removed and replaced easily. In the event that the tooth is broken, it can be dressed by repair and then reinstalled. Perhaps this will become more apparent on description of the stump grinder in operation. To consider the device somewhat more carefully, a stump grinder is often required to lower the protruding stump to a level which is below grade so that it does not interfere with lawn maintenance equipment. In an agricultural setting, the stump may have to be removed even below the surface so that it no longer interferes with spring time plowing or other pasture or farm maintenance. For instance, a small stump may not pose much of a problem to a gang plow pulled behind a tractor, but a stump of perhaps 12 inches diameter, even when cut to grade level, might snag one plow of the gang and either break it, or deflect the multiple plow points pulled in the gang and divert or misdirect the plowed furrows. In that instance, it is necessary to grind away the stump to the point that it is significantly below grade. This is necessary to assure that the plows do not snag on that stump at any of the plow points.
Stump removal has a good deal of value to those who keep a nice lawn. But, the value is equally as important to farmers and ranchers. Commonly, stump grinding tools use a type of cutting device. The cutting device is brought against the stump to grind it away. Surprisingly, stump removal can be relatively difficult in that the context is often somewhat risky. By that, references made to the fact that the area or region where the stumps are located may very well be in new construction where the construction itself is a construction site strewn with buried trash. In that instance, the buried trash can pose a serious risk to the stump grinder because it may well include trash which is unusually difficult or hard to deal with. Consider, for instance, a stump which is located below grade and is in a region where construction trash was dumped. That may well include buried pieces of concrete including reinforcing bars, etc. This poses some degree of risk. The risk is often endangered by breaking a tooth or more than one tooth. In this particular instance, the present apparatus enables quick and easy servicing, thereby permits replacement of an individual tooth or replacement of several teeth, depending on how many might be damaged.
The tooth construction of this disclosure utilizes a tool body which will be defined as the tooth root. That term will be defined below. Essentially, while it does not cut, it has the form of a long root which can be clamped and connected with the cutter wheel. That term will be defined also. Going more importantly to the contact region, this disclosure sets forth a polycrystalline diamond compact (PDC herein below) which is affixed to the tooth. In the preferred forms, there being two or three different forms given, the tooth is constructed with a root of tool steel of sufficient resiliency that it is not brittle and has a measure of give. A neck on the tool is located toward one end of the root. The neck terminates at a planar region having a specified angle with respect to the direction of rotation. Accordingly, the neck terminates in a face and the face region is used to support the attached PDC member. In the preferred embodiment, the PDC member is preferably a circular disc having a diameter of up to about 1.125" at one extreme to about 0.50" for the preferred size, and up to about 2.375" inches at the larger extreme. The PDC thickness is somewhere between about 10 to about 120 mils. The PDC layer is commonly made in sizes which falls well within the range just mentioned. It is attached by an underlayer supporting it and serving as an adhesive for attachment to the tooth. Being attached at the end of the root, it is positioned so that it contacts against the stump.
While one would readily suppose that cutting stumps, i.e., cutting wood is somewhat easier, there is the risk of underestimating the difficulty of the chore. More specifically, the cutting face does not just contact wood. It is brought into contact with dirt, fill sand, and any other piece of buried debris which might be in the area. This creates a measure of risk to the equipment. This also creates a severe wear factor at the time of contact against the unwanted debris which is in the way. The cutting action accomplished by this is done on a rotating wheel. The wheel rotates at a steady or stable speed determined by the tractor or other equipment which operates it. One such tractor is the model 252 stump cutter which is provided by Vermeer, a known source of stump cutters. The model just mentioned is a device which weighs about 1,040 pounds and which is powered by a 25 horsepower motor. Other versions use a 20 horsepower motor. The motor will typically operate a hydraulic system which in turn, rotates the cutting wheel. In the one just mentioned, the cutting wheel diameter is about 16 inches without teeth, and about 19 inches with the teeth. It typically has a thickness of about five inches and is rotated at a speed of about 1,250 rpm and supports cutting teeth which are received in suitable pockets. Commonly, 16 teeth will suffice for the cutting wheel. When operated at the above described speed, it has the powerful effect of grinding a stump and turning it into small wood chips and shavings which are scattered around. It is preferably swept to the left and right to grind away the stump and to reach underground. As will be understood, that is often when unintended accidents occur and teeth are badly damaged or broken away. The present disclosure sets forth a replacement tooth for this sort of device.
Moreover, it is replacement tooth which provides enhanced life and which is able to assure that the teeth can be easily replaced and the cutting action continued.